The present invention disclosed herein relates to a radio frequency (RF) device, and more particularly, to an RF device including a carbon nanotube.
Typically, an RF receiver includes an antenna, a modulator, a filter, and an amplifier, which limits the size and power of subminiaturized wireless devices. RF applications are widely applied to local area identification devices such as radio-frequency identification (RFID) devices, and wide area detection or communication devices such as mobile communication devices and radars. Such an RF receiver includes discrete RF components such as an antenna, a filter, a demodulator, and an amplifier. Commonly, RF components are respectively formed according to discrete manufacturing methods, and then connected to each other in a single chip through packaging. Alternatively, RF components may be realized by forming various devices directly on the same substrate. In this case, it is difficult to apply the RF components to implanted subminiaturized devices because of their size and power consumption, or to realize sensor nodes applied to wireless sensor network.
To address these limitations, methods of miniaturizing RF components using a micro-electro-mechanical system (MEMS) technology are being extensively developed. For example, small-sized antennas having a cantilever bridge structure or trampoline structure are realized with the MEMS technology, and a plurality of MEMS capacitors can perform a tuning function of a RF device. To obtain a desired frequency variation width of the MEMS capacitors, a high driving voltage is required, and structures having a size of several hundreds micrometers must be precisely controlled.
RFID devices are required to have low power consumption and a subminiature size. Particularly, such RFID devices must be realized on flexible substrates, such as plastic substrates. When antennas are formed using the MEMS technology, the antennas are susceptible to deformation, and integration circuits such as amplifiers are difficult to realize through an identical chip process. Recently, a printable technology such as an inkjet printing or roll-to-roll process is rising as a core technology for manufacturing RFID devices. It is necessary to link technologies of manufacturing RFID devices to printable process technologies. Thus, there is required an RF receiver including a micro antenna, which achieves subminiaturization, low power consumption, and high sensitivity more easily.
Such an RF receiver including an RFID device can be applied to overall future fusion technology devices such as implanted micro devices, or sensor nodes for wireless sensor network.